Current cell culture devices (e.g. cell culture plates, cell culture dishes) are designed as lid and base systems wherein a separate base and lid are paired together to provide a cell culture environment. The base provides the cell culturing area of the device while the lid acts as a cover to protect the cell culturing area from particulate and microbiological contamination and, in some applications, to limit evaporation of media from the cell culturing area. Current cell culture devices include lid designs with a full skirt that generally inhibit the user from gaining easy capture of the base between a thumb and finger to allow the device to be easily picked up. The low profile (i.e. low side wall height) of the base of these devices when combined with the relatively long skirt of the lid often result in a situation where the lid is presented as the major contact surface for the user as they attempt to pick the device up from a storage location, a work surface, or a stack of like devices. In the best case outcome, the user exercises extreme care to capture the lid and base as a pair in order to move the pair from one place to another. In a less ideal outcome, the user inadvertently removes the lid during the device manipulation which, in turn, can result in cell culture contamination. In the worst case outcome, the full skirt of the lid inhibits the user from making robust contact with the base and leads to the user dropping the device during manipulation. Hence, there is a need for an improved design of lidded cell culture devices and this need is more readily apparent in view of the following detailed discussion about current cell culture devices and some of the additional problems associated with current cell culture devices.
Typically, cell culture plates have square or rectangular footprints. Examples of cell culture plates are multiple well assay plates, microwell plates, and in vitro fertilization (IVF) plates. In contrast, cell culture dishes typically have circular footprints. An example of a cell culture dish is the common petri dish which has been used in the laboratory environment since the 1880s. FIG. 1 (PRIOR ART) provides a representation of an exemplary traditional petri dish 100. The traditional petri dish 100 has a circular base 102 and a circular lid 104. The circular base 102 has a flat bottom panel 106 and a base sidewall 108 extending substantially perpendicularly upward from the flat bottom panel 106. The circular lid 104 has a lid panel 110 and a lid sidewall 112 extending substantially perpendicularly downward from the lid panel 110. The inner diameter of the of the lid sidewall 112 is greater than the outer diameter of the base sidewall 108 such that the circular lid 104 when set on the circular base 102 covers the circular base 102 with the lid sidewall 112 extending over and covering the top of the base sidewall 108. The base sidewall 108 is of greater height than the depth of the lid sidewall 112.
Lidded cell culture devices (e.g. cell culture plates, cell culture dishes) are used in various fields including, for example, microbiology, cell culturing, tissue culturing, cell assays, and IVF. The currently marketed designs for cell culture dishes include fully skirted lids that have larger diameters than their respective bases. The currently marketed designs for cell culture plates include fully skirted lids with overall widths and lengths greater than their respective bases. The fully skirted design approach provides a lid that wraps over the side wall of the base to keep the lid located over the base. However, this lid design when combined with the standard low profile base design typically results in the lid skirt obscuring the base sidewall making it difficult to lift the plate or dish concurrent with its mounted and paired lid. Oftentimes the lid must be removed from the plate or dish in order lift and move the plate or dish base. Alternately, the user must carefully pinch both the lid and base between their thumb and finger concurrently to lift both the lid and base as a pair. As the overall dimension of the lid is greater than the overall dimension of the base and as the profile of the base is typically low, trying to concurrently capture both the lid and base by pinching a thumb and finger against them is very difficult. Often the user will rock the cell culture device off of the work surface slightly to gain contact of their thumb or finger to a small portion of the height of the base that is not obscured by the lid. This is especially true for cell culture dishes, as currently marketed dish designs include lid skirts of greater diameter than their paired base skirt diameter. Media spillage can readily occur as the user rocks the cell culture device in their attempt to capture both the lid and base. Hence, improved designs of cell culture devices are needed to address this problem.
Most current cell culture plate designs include a base skirt of sufficient height to allow the user to pick up the base and lid concurrently by capturing the base skirt between their thumb and finger. These plate designs, however, require the total height of the base to be greater than is absolutely required, include a lower profile lid skirt, or provide a lid skirt that is shorter than the ideal height to allow easy gripping by a thumb and finger. Even with this base skirt design, plate users often experience difficulty moving the cell culture plate without risk of inadvertently removing its paired lid. Or, avoiding this issue, the user has to make a concerted effort to capture the base skirt between their thumb and finger due to the relatively low profile of the base skirt. Current designs for cell culture dishes do not include a base skirt, but rather depend on the manual agility of the user to pinch a portion of both the lid skirt and base wall concurrently in order to lift a paired base and lid. The difficulty of capturing the lid and base concurrently in all of these cell culture dish and plate designs is compounded by the fact that the user is typically wearing plastic gloves and manipulating the cell culture device within the tight confines of a laboratory laminar flow hood. Hence, improved designs of cell culture devices are needed to address this problem.
Further, it is well understood that effective cell culturing entails the minimization of the potential introduction of contaminants such as particulate or unintended microbes to the cell culturing area within the cell culture devices. As the probability of contaminating the cell culturing area within a cell culture device is directly proportional to the number of times that the device lid is removed during the cell culturing process, it is evident that cell culture device designs should minimize the frequency that lids are unnecessarily removed from their bases. However, current cell culture devices are designed with lids that protrude beyond the base walls of the devices and this common lid and base design makes it difficult for the user to lift the lidded pair concurrently. As a result, current cell culture devices often experience unnecessary lid removal and, therefore, unnecessary exposure to contaminants when simply trying to transfer the device from one place to another within the laboratory environment. Hence, improved designs of cell culture devices are needed to address this problem.
Additionally, the user often performs other operations (e.g. pipetting, visual inspection of cells, microscopic inspection of cells) during cell culturing operations. During pipetting, the user typically holds a pipettor in their dominant hand while manipulating stacks and individual cell culture devices with their other, i.e. non-dominant, hand. This leaves the user in the undesirable position of handling a cell culture device that is often small and difficult to lift as a lid and base pair using their non-dominant hand. Hence, improved designs of cell culture devices are needed to address this problem.
Finally, though not necessarily a best practice during cell culturing processes, there are occasions when the user may place the lid of the cell culture device on a laboratory work surface. Current lid designs include a full skirt that leads to the potential that the lid becomes stuck to the laboratory work surface due to the creation of an area of lower air pressure (i.e. a relative vacuum) beneath the lid. This is especially true when the lid is removed from the base and set down such that the lid skirt is placed in contact with a wetted work surface. Hence, improved designs of cell culture devices are needed to address this problem.
Designers and manufacturers of cell culture devices have tried to address at least some of these problems by, for example, designing higher profile (i.e. higher side wall height) bases and/or shorter skirts on lids so as to minimize the lid skirt profile in comparison to the base sidewall profile. However, improved designs are still needed to address the aforementioned problems associated with the current lidded cell culture devices (e.g. cell culture plates, cell culture dishes).